John 3

"He who believes in the Son has eternal life; but he who does not obey the Son will not see life” (v36).  Jesus said that “whoever believes in Him will not perish but have eternal life” (v16).  He called the disciples to follow him, and we must also obey Him in order to “see life.”  These phrases – believing, following, and obeying - are all part of the same commitment to Christ. 

“Coming into the light” (v21) includes all these things.  Believing, following, and obeying are heart-responses to the love of God poured out in the Son.